In summary. The graph of each equation is a straight line, m is the gradient of the line and c is the y-intercept. Conversely, if a straight line has gradient m and y-intercept c it has equation y = mx + c.
He has done 70 push ups because by the 15th he has done 35 push ups add 15 more days and u get 70 .
<em>1/3 is answer. Hope it helps
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ANSWER
Find out the how much fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
To proof
let us assume that the fluid should be drained and replaced with pure antifreeze be x .
As given
A radiator contains 10 quarts of fluid, 30% of which is antifreeze.
Now write 30% in the decimal form

Now write 60% in the decimal form

After drained and replaced the fluid with pure antifreeze than the quantity becomes = ( 10 - x )
The quantity of antifreeze is

The fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
than the equation becomes

solyving
100x +300 - 30x = 600
70x = 300

x = 4.28 quarts (approx)
Hence 4.28 quarts (approx) fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
Therefore the option (c.) is correct .